Demi Moore has finally pulled the trigger and filed for divorce from Ashton Kutcher -- 16 months after they split up!

And get this -- Demi is asking for spousal support, plus she wants him to pay her attorney's fee. Sources says it's a strange move considered she's worth millions more than Ashton.

Ashton, who filed for divorce about four months ago, is not asking for spousal support from Demi. TMZ says both sides are negotiating and they expect a quick resolution.